In a conventional art, a communication terminal having a wireless LAN function needs to perform a wireless connection or a security setup to join a network (infrastructure network), which is provided via an access point (hereinafter, abbreviated as AP). This setup requires various settings to be input on the communication terminal. Since this input of the settings has been complex, it is particularly difficult for a user unfamiliar with wireless LAN technology to perform the setup.
To resolve this problem, Wi-Fi Protected Setup™ specification 1.0 (hereinafter, abbreviated as WPS) is disclosed as industrial standard technology of a wireless LAN for allowing a communication terminal to join an infrastructure network by simply performing a wireless connection or a security setup in Non-patent Document 1. Non-patent Document 1 is available, for example, from https://www.wi-fi.org/knowledge_center_overview.php?type=4.
Some setup methods are defined in the WPS, and a scheme using a PIN code that is identification information for an indication of a wireless network (hereinafter, abbreviated as PIN scheme) is defined as one of the methods. In the PIN scheme, the setup can be performed by inputting, to an AP, a PIN code that is displayed on an external terminal with a wireless LAN function desiring to join a network. The input of the PIN code to the AP may be performed, for example, by inputting the PIN code from a terminal in the network of the AP using a browser.
Meanwhile, in recent years, an ad hoc mode in which communication terminals directly perform wireless LAN communication with each other, unlike an infrastructure mode needing an AP, has begun to be introduced to portable terminals such as game machines or cameras. In the ad hoc mode, a central terminal, like the AP in the infrastructure mode, is not present in a network, and respective terminals perform communication on even ground. In Non-patent Document 2 disclosed as http://standards.ieee.org/getieee802/download/802.11-2007.pdf, a communication method in an infrastructure mode and an ad hoc mode is described.
In the ad hoc mode, a wireless connection or a security setup is complex as in the infrastructure mode, and it is desirable for a conventional WPS to be applied even to the ad hoc network to be run. Further, since respective terminals are on even ground, it is necessary to determine a terminal to display the PIN code or a terminal to input the PIN code when each terminal is capable of both displaying and inputting the PIN code.